KABUL — Western forces killed four Afghan troops Saturday in an airstrike, and military officials disclosed that an Afghan interpreter had shot dead two U.S. service members a day earlier, in a rare concentration of deaths at the hands of allies.
Even more unusually, the lethal incidents occurred in the same district of Wardak province, west of the capital, Kabul, but officials said they did not appear to be related.
The deaths came on the heels of a conference in London at which nations contributing troops and aid to Afghanistan worked to lay the groundwork for an eventual Western withdrawal.
Central to that scenario is the close cooperation of Afghan security forces and foreign mentors as Afghans prepare to assume responsibility some years from now for safeguarding the country.
But relations between the two sides are sometimes marked by mistrust.
The NATO airstrike on an Afghan army outpost marked the second friendly fire incident in less than three months that has killed several Afghan troops. Accounts by both sides suggested that in predawn darkness and amid rugged territory, Western and Afghan troops mistook each other for insurgents, setting off a clash.
NATO expressed regret over the incident, but in a reflection of continuing tensions between Western forces and the government of President Hamid Karzai, the Defense Ministry issued a harshly worded statement demanding that those responsible be punished.
More than 24 hours after the deaths of two U.S. service members at the hands of an Afghan interpreter, the details remained unclear.
After firing on the Americans, the interpreter was shot and killed by another U.S. soldier.